Measuring the inner body temperature using a wireless temperature SAW-sensor-based system

Abstract

In this work, the possibility to measure the temperature of the inner body is addressed. For the present study, we have used Rayleigh wave resonators built on (ST,X) quartz for validating the interrogation principle. These resonators must be packaged to enable ingestion and transit via the digestive canal. A particular antenna design is then proposed, allowing for reducing the whole sensor size down to a 3.5 cm long 0.8 cm radius cylinder that contains both the antenna and the SAW resonators. In vivo tests have been performed on a dog, demonstrating the capability of our setup to wirelessly interrogate the ingested SAW resonators. In the first section of the paper, we briefly introduce the gastro-intestinal system and the associated medical diagnostic problems. We also briefly recall the principle of our interrogation system. For in vivo tests, we have used an altuglass package previously developed at INSERM Strasbourg tested for different low invasive operations in the gastro- intestinal system. The efficiency of the system is reported and first tests on living animals are presented and discussed. Some simple analysis elements are finally proposed to simulate the response of the ingested SAW resonators.